Abrasive cutting system and method

ABSTRACT

A high pressure fluid jet system is provided, which is useful for cutting hard material during a surgical procedure. The cutting of hard material is more efficient as the system delivers abrasive solid particles with the high pressure fluid. In an exemplary embodiment, abrasive solid particles can be mixed with a pressurized stream of fluid prior to delivery of the fluid to a nozzle of an application tool. Alternatively, the abrasive solid particles can be entrained in the pressurized fluid stream or the pressurized fluid stream can erode a solid or suspension form of the abrasive particles.

FIELD OF THE INVENTION

The present invention relates to high pressure fluid jet surgical tools,and in particular to a high pressure fluid jet tool for cutting hardmaterial during a surgical procedure.

BACKGROUND OF THE INVENTION

Fluid pressure-based surgical tools for cutting bone and the like canoffer some advantages over traditional surgical cutting devices andmethodologies. In particular, high pressure fluid jets tend to emulsifythe target material, thus avoiding thermal damage which can arise fromusing laser cutters and electrosurgical cutters. The emulsified materialcan also be easily transported away from the surgical site byaspiration. Indeed, the fact that many high pressure fluid jet cuttingdevices include aspiration and evacuation as an integral portion of thedevice can be an added benefit for many surgical procedures.

One drawback associated with current fluid pressure-based surgicalsystems which are used to cut bone and the like is that they typicallyrequire ultra-high operating pressures, and the delivery of suchhydraulic pressure using a conservatively sized operating room pump andsurgical instruments delicate enough to meet the surgeon's demands canoften be problematic.

Accordingly, there remains a need for an improved fluid pressure-basedsurgical tool, and in particular a fluid pressure-based surgical toolfor cutting hard material.

BRIEF SUMMARY OF THE INVENTION

Various methods and devices are provided for cutting hard material, suchas bone and the like, during a surgical procedure. In one exemplaryembodiment, a method is provided which includes delivering a pressurizedstream of fluid through a surgical tool to effect cutting of hardmaterial within a patient. While a variety of fluids can be used toeffect cutting, by way of non-limiting example, the fluid that cuts thehard material includes a delivery liquid having a plurality of abrasivesolid particles formed from an organic material. The abrasive solidparticles can be formed from a variety of materials, and in an exemplaryembodiment they are formed from bioabsorbable materials such aspolyglycolic acid, polylactic acid, polyethylene oxide, and blends andcopolymers thereof.

The present invention also provides various methods for mixing theabrasive solid particles with the delivery liquid, such as, for example,mixing the abrasive solid particles with the pressurized stream of fluidprior to delivery through the nozzle. In another embodiment, theabrasive solid particles can be entrained in the pressurized fluidstream after the pressurized fluid stream exits the nozzle, or,alternatively, the abrasive solid particles be in the form of a solid orsuspended material that is eroded by the pressurized fluid stream oncethe fluid stream exits the nozzle. While the solid material can be avariety of shapes, by way of non-limiting example, the solid materialcan be a rod. Moreover, the solid material can be a plate having a solidregion and an open region. The open region of the plate can be a varietyof configurations, and in one embodiment it can be formed in a varietyof shapes and of a material such that when the plate is contacted by thepressurized fluid stream, the hard material is cut in a pattern that iscomplementary to the shape of the open region.

The present invention also provides a system for cutting tissue during asurgical procedure which includes a surgical apparatus effective todeliver a stream of pressurized fluid and a plate with a cuttingtemplate. The cutting template can have a variety of configurations, andin one embodiment, the cutting template can have a region formed of asolid material which is resistant to erosion by the pressurized fluidand an opening formed in said region which is able to be occluded by anerodable plug of abrasive material.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more fully understood from the following detaileddescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1A is a schematic illustration of a high pressure fluid jet systemaccording to one embodiment of the invention;

FIG. 1B is a schematic illustration of a suspension pump for use withthe high pressure fluid jet system of FIG. 1A;

FIG. 2 is a schematic illustration of one embodiment of the presentsystem utilizing a collimating nozzle which allows abrasive solidparticles to be entrained within a pressurized stream of fluid;

FIG. 3 is a schematic illustration of another embodiment of the presentsystem utilizing a high pressure fluid jet system having a supply ofabrasive solid particles;

FIG. 4A is a schematic illustration of a further embodiment of thepresent system utilizing a high pressure fluid jet system for use with acutting template that is eroded by a pressurized stream of fluid; and

FIG. 4B is top perspective view of a cutting template for use with thehigh pressure fluid jet system of FIG. 4A.

DETAILED DESCRIPTION OF THE INVENTION

Certain exemplary embodiments will now be described to provide anoverall understanding of the principles of the structure, function,manufacture, and use of the methods and devices disclosed herein. One ormore examples of these embodiments are illustrated in the accompanyingdrawings. Those skilled in the art will understand that the methods anddevices specifically described herein and illustrated in theaccompanying drawings are non-limiting exemplary embodiments and thatthe scope of the present invention is defined solely by the claims. Thefeatures illustrated or described in connection with one exemplaryembodiment may be combined with the features of other embodiments. Suchmodifications and variations are intended to be included within thescope of the present invention.

The present invention provides a high pressure fluid jet system that isuseful, during a surgical procedure, for cutting hard material. Thecutting of hard material is more efficient as the system deliversabrasive solid particles with the high pressure fluid. In an exemplaryembodiment, abrasive solid particles can be mixed with a pressurizedstream of fluid prior to delivery of the fluid to a nozzle of anapplication tool. Alternatively, the abrasive solid particles can beentrained in the pressurized fluid stream or the pressurized fluidstream can erode a solid or suspension form of the abrasive particles.One skilled in the art will appreciate that the present invention can beused to cut a variety of hard materials, such as bone, cartilage, bonecement, bioadhesives, or any other hard material found or used within ahuman body, and therefore can be used in a wide range of surgicalprocedures.

A variety of materials can be used to form the abrasive particles of thepresent invention, including organic and inorganic materials. In anexemplary embodiment, the abrasive particles are biocompatible andbioabsorbable. One skilled in the art will appreciate that the materialscan be crystalline or amorphous. Further, the crystalline materials caninclude ice and other frozen materials.

Examples of suitable bioasborbable materials that can be used to formthe abrasive particles include polymers selected from the groupconsisting of aliphatic polyesters, poly(amino acids),copoly(ether-esters), polyalkylenes oxalates, polyamides, tyrosinederived polycarbonates, poly(iminocarbonates), polyorthoesters,polyoxaesters, polyamidoesters, polyoxaesters containing amine groups,poly(anhydrides), polyphosphazenes, biomolecules (i.e., biopolymers suchas collagen, elastin, bioabsorbable starches, etc.), and any blends andcopolymers thereof.

For the purpose of this invention aliphatic polyesters include, but arenot limited to, homopolymers and copolymers of lactide (which includeslactic acid, D-,L- and meso lactide), glycolide (including glycolicacid), ε-caprolactone, p-dioxanone (1,4-dioxan-2-one), trimethylenecarbonate (1,3-dioxan-2-one), alkyl derivatives of trimethylenecarbonate, δ-valerolactone, β-butyrolactone, γ-butyrolactone,ε-decalactone, hydroxybutyrate, hydroxyvalerate, 1,4-dioxepan-2-one(including its dimer 1,5,8,12-tetraoxacyclotetradecane-7,14-dione),1,5-dioxepan-2-one, 6,6-dimethyl-1,4-dioxan-2-one 2,5-diketomorpholine,pivalolactone, α, α diethylpropiolactone, ethylene carbonate, ethyleneoxalate, 3-methyl-1,4-dioxane-2,5-dione,3,3-diethyl-1,4-dioxan-2,5-dione, 6,8-dioxabicycloctane-7-one andpolymer blends thereof. Poly(iminocarbonates), for the purpose of thisinvention, are understood to include those polymers as described byKemnitzer and Kohn, in the Handbook of Biodegradable Polymers, edited byDomb, et. al., Hardwood Academic Press, pp. 251-272 (1997).Copoly(ether-esters), for the purpose of this invention, are understoodto include those copolyester-ethers as described in the Journal ofBiomaterials Research, Vol. 22, pages 993-1009, 1988 by Cohn and Younes,and in Polymer Preprints (ACS Division of Polymer Chemistry), Vol.30(1),page 498, 1989 by Cohn (e.g., PEO/PLA). Polyalkylene oxalates, for thepurpose of this invention, are understood to include those described inU.S. Pat. Nos. 4,208,511; 4,141,087; 4,130,639; 4,140,678; 4,105,034;and 4,205,399. Polyphosphazenes, co-, ter- and higher order mixedmonomer based polymers made from L-lactide, D,L-lactide, lactic acid,glycolide, glycolic acid, para-dioxanone, trimethylene carbonate andε-caprolactone are understood to be those as are described by Allcock inThe Encyclopedia of Polymer Science, Vol. 13, pages 31-41, Wileylntersciences, John Wiley & Sons, 1988 and by Vandorpe, et al in theHandbook of Biodegradable Polymers, edited by Domb, et al., HardwoodAcademic Press, pp. 161-182 (1997). Polyanhydrides are understood toinclude those derived from diacids of the formHOOC—C₆H₄—O—(CH₂)_(m)—O—C₆H₄—COOH, where “m” is an integer in the rangeof from 2 to 8, and copolymers thereof with aliphatic alpha-omegadiacids of up to 12 carbons. Polyoxaesters, polyoxaamides andpolyoxaesters containing amines and/or amido groups are understood to bethose as described in one or more of the following U.S. Pat. Nos.5,464,929; 5,595,751; 5,597,579; 5,607,687; 5,618,552; 5,620,698;5,645,850; 5,648,088; 5,698,213; 5,700,583; and 5,859,150. Finally,polyorthoesters are understood to be those as described by Heller inHandbook of Biodegradable Polymers, edited by Domb, et al., HardwoodAcademic Press, pp. 99-118 (1997).

Exemplary bioabsorbable materials include, but are not limited to,polygylcolic acid, polylactic acid, and polyethylene oxide, and blendsand copolymers thereof. Alternatively, inorganic materials can be usedto form the abrasive particles, such as, for example, tricalciumphosphate.

The resulting abrasive particles can be any size which allows foreffective cutting of the hard material, while at the same time does notdeteriorate the nozzle of the high pressure fluid jet. In an oneembodiment, the abrasive particles can have a size in the range of about5 microns to 200 microns, depending upon when the abrasive particles aremixed with the pressurized stream of fluid. For example, if the abrasiveparticles are mixed with the high pressure jet prior to the highpressure jet flowing through the nozzle, the abrasive particles can besized so as not to clog or diminish the performance of the nozzle. Thus,in an exemplary embodiment, the abrasive particles may be sizedsubstantially smaller than the size of the nozzle, such as, for example,in the range of about 5 microns to 20 microns. Alternatively, forapplications involving mixing the abrasive particles after the highpressure jet leaves the nozzle, where clogging or diminishing theperformance of the nozzle is not as great of a concern, the particlescan be a variety of sizes, such as, for example, in the range of about 5microns to 200 microns.

While virtually any type of high pressure fluid jet system can be usedwith the various embodiments disclosed herein, the system generallyincludes a drive mechanism and a fluid source. While the fluid sourcecan utilize a variety of fluids that can safely be delivered into thehuman body, in an exemplary embodiment, the fluid is saline. Further,the fluid can flow through the system at various rates depending uponthe type of material desired to be cut, however the pressure of thestream of fluid is generally in the range of about 5 to 50,000 psi, morepreferably in a range of about 1,000 to 20,000 psi, and most preferablyin a range of about 5,000 to 15,000 psi. Following the combination ofthe abrasive materials and delivery liquid with the pressurized streamof fluid, the concentration of abrasive materials within the pressurizedstream of fluid is generally no more than about 30% by volume, and morepreferably in the range of about 5%-20% by volume.

FIG. 1A illustrates one exemplary embodiment of a high pressure fluidjet system 10 that is useful to cut hard materials in a surgicalprocedure by combining particles of an abrasive material with a streamof pressurized fluid. As shown, the system 10 can include a fluid source20, such as a saline, that is in fluid communication with a drivemechanism 16. The drive mechanism 16 communicates the fluid to asuspension pump drive mechanism 31 such that a concentrated suspensionof abrasive particles and delivery liquid, such as saline, (the“slurry”) 33 can be combined with a pressurized stream of fluid prior tothe pressurized stream of fluid entering a fluid jet delivery device oran application tool 28. The fluid source 20 can be coupled to the drivemechanism 16 using a variety of techniques, but in one exemplaryembodiment the fluid source 20 includes a conduit 26 (discussed in moredetail below) that extends between the fluid source 20 and the drivemechanism 16. Likewise, the drive mechanism 16, the suspension pumpdrive mechanism 31, and the application tool 28 can also be connected bya conduit 26 extending therebetween. A person skilled in the art willappreciate that the high pressure fluid jet system can include a varietyof other components, and that each component can have a variety ofconfigurations. Moreover, the components can be integrally formed withone another or they can be removably attached to one another.

While virtually any known drive mechanism 16 can be used, the drivemechanism 16 can include a pump console 22 for pumping fluid from thefluid source 20 through a pump cartridge (not shown) at a controlledrate. The exemplary pump console 22 can include a push rod that isdriven by a motor disposed within the pump console 22, and that includescontrols to allow a user to input the desired pump parameters. In use,the motor is effective to reciprocate the push rod along its axis,thereby reciprocating a piston disposed within the pump cartridge topump fluid through the cartridge towards the application tool 28.

Connected to drive mechanism 16 (by conduit 26) is a suspension pumpdrive mechanism 31 which delivers a concentration of slurry 33 into thepressurized stream of fluid. The slurry can include any combination ofthe abrasive materials disclosed herein mixed or suspended within adelivery liquid, e.g., saline. However, by way of non-limiting example,the slurry contains at least about 40% of abrasive solid particles byvolume, and in a preferred embodiment at least about 20% of abrasivesolid particles by volume. The suspension pump drive mechanism 31 issimilar to the drive mechanism 16 and, as shown in FIG. 1B, has a slurrypump console 30 which can include a piston 40 which slidably moveswithin a pump cavity 38 such that the slurry is pushed into thepressurized stream of fluid.

The pump cavity 38 of slurry pump console 30 can have a variety ofconfigurations, however it generally is complementary in shape to thepiston 40 and has an inlet port 32 through which the slurry enters thecavity 38 and an outlet 36 through which the slurry exits the cavity toultimately mix with the pressurized stream of fluid. The inlet port 32can be of any size, shape and configuration that renders it capable oftransporting the slurry. In one embodiment, however, it is a conduit 26(discussed in more detail below) reversibly or integrally mated to avalve mechanism 34. A variety of valve mechanisms 34 can be used so longas they are capable of controlling the rate and amount of slurry whichenters into the cavity 38, such as, for example, a manual valve, atwo-way valve, a one-way valve, or an automatically or electronicallycontrolled valve. One skilled in the art will appreciate that theability to control the amount of slurry entering the cavity 38, andultimately the application tool 28, allows a surgeon to perform avariety of different procedures using a variety of different abrasivematerials.

While the piston 40 can have any known configuration, the piston 40 isgenerally constructed so that it is able to move within the pump cavity38 such that the slurry is dispensed through an outlet 36 towards theapplication tool. The outlet 36 can also be of any configuration knownin the art to transport the slurry, however, by way of non-limitingexample, it is an integrally formed or removably mated conduit 26 (suchas is discussed below). Once the slurry is dispensed through the outlet36, the piston 40 can then retract, thereby allowing slurry to refillthe pump cavity 38.

Referring back to FIG. 1A, the fluid delivery conduit 26 can also have avariety of configurations. In one exemplary embodiment, the fluiddelivery conduit 26 can be formed from a material which has sufficientburst strength to safely deliver fluid at a high pressure to theapplication tool 28. The material should also be flexible to enable asurgeon to manipulate the application tool 28 freely. The fluid deliveryconduit 26 can also include connectors, which in an exemplary embodimentcan be hand tightened, to connect the ends of the fluid delivery conduit26 to the fluid source 20, drive mechanism 16, suspension pump drivemechanism 31, and/or application tool 28, where detachable componentsare desired. As previously indicated, the fluid delivery conduit 26 canbe integrally formed with or removably mated to the fluid source 20,drive mechanism 16, suspension pump drive mechanism 31, and/orapplication tool 28.

The application tool 28 can also have a variety of configurations, andvirtually any device for forming a high pressure fluid jet can be usedwith the various embodiments disclosed herein. For example, theapplication tool 28 can include a lumen in fluid communication with thedelivery conduit 26 and a nozzle for forming a high pressure fluid jet.The application tool 28 can also include an evacuation lumen forcollecting and withdrawing fluid, as well as a variety of other featuresfor facilitating use of the device. By way of non-limiting example, oneexemplary embodiment of a fluid jet device is disclosed in commonlyowned U.S. patent application Ser. No. 10/904,456 filed on Nov. 11, 2004and entitled “Methods and Devices for Selective Bulk Removal andPrecision Sculpting of Tissue” by McRury et al.

FIG. 2 illustrates another embodiment of the present invention in whichabrasive particles are entrained in a pressurized stream of fluid 114after the fluid exits a nozzle 128 of an application tool or fluid jetdelivery device. As shown, a second, collimating nozzle 131 surroundsthe nozzle 128 of the application tool and forms a cavity 129 whichmaintains the slurry around the nozzle so that when the pressurizedstream of fluid 114 enters the cavity 129, some of the abrasiveparticles in the slurry become entrained within it, and theabrasive-containing pressurized stream of fluid exits the cavity 129through opening 125.

While the collimating nozzle 131 can have a variety of shapes, in oneembodiment the collimating nozzle 131 has a shape which complements theshape of the nozzle 128 of the application tool. The collimating nozzle131 can also have an inlet port 127 which allows for the entry of theslurry into the cavity 129, and in a preferred embodiment, the inletport 127 includes a conduit (not shown) which is connected to a largesupply of the concentrated slurry.

While the cavity 129 can be a variety of shapes, as shown, the cavity129 is complementary to the shape of the collimating nozzle 131. Thecavity 129 further can be a variety of sizes, however it should be largeenough to maintain a presence of slurry around the nozzle 128 of theapplication tool. In use, once the cavity 129 is filled with slurry, thepressurized stream of fluid 114 flows into the cavity 129 via the nozzle128. The influx of the pressurized stream of fluid 114 into the cavity129 creates suction or a vacuum within the cavity 129, and, as a result,the slurry becomes entrained with the pressurized stream of fluid 114.The abrasive-containing pressurized fluid stream exits opening 125 inthe collimating nozzle 131, and can then be used to cut hard materialupon contact. One skilled in the art will appreciate that thisembodiment provides the option of on-demand control to engage and/ordisengage the flow of the abrasive material.

FIGS. 3-4B illustrate alternative embodiments of the present inventionin which the pressurized fluid stream can erode a suspension or solidform of the abrasive material resulting in the abrasive solid particlesbecoming entrained within the pressurized stream of fluid. Referringfirst to FIG. 3, the pressurized stream of fluid 214 flows out of thenozzle 228 of the high pressure jet 212 and contacts a supply 211 whichcontains the abrasive material. Once the pressurized stream of fluidcontacts the supply 211, a portion of the abrasive material is eroded,resulting in abrasive particles becoming entrained within thepressurized stream of fluid 214 such that hard material 200 can be cutupon contact.

One skilled in the art will appreciate that the supply 211 of abrasivematerial can be a variety of forms, depending upon the type of materialused. In exemplary embodiments, the supply 211 can be a solid which isrod-shaped (as shown), cylindrical, or any other shape, or a suspension.Further, the supply 211 can have any configuration which can hold theabrasive material, such as, for example, a conduit. The supply 211 canbe directed to the pressurized fluid stream 214 in a variety of ways,however, in an exemplary embodiment it is cross-fed into the pressurizedfluid stream 214. One skilled in the art will further appreciate thatthis embodiment requires a very short residence time of the abrasivebefore it is delivered to the hard material, so that abrasive materialsother than those mentioned above, such as crushed ice, may be used.

FIGS. 4A-4B illustrate an alternative embodiment of the presentinvention in which the pressurized stream of fluid 214 erodes a portionof a cutting template 257 placed on the hard material 200. The cuttingtemplate 257 can be any form which allows for hard material to be cut ina desired pattern, however, by way of non-limiting example, the template257 can have a solid region 262 and an open region 260, as shown in FIG.4B. The solid region 262 can be made of any biocompatible material suchas a metal (e.g., stainless steel) or a polymer (e.g., high densitypolyethylene or Polyetherether Ketone (PEEK)), or any other materialthat will not erode when contacted by the pressurized stream of fluid.The solid region 262 can also be a variety of shapes, such as a plate ora cartridge, so long as the shape can contain within it an open regionor cutting region (such as open region 260, for example) having anagglomerate of abrasive material. The open region 260 can be formed fromany occlusion of the abrasive materials listed herein and can be avariety of shapes depending upon the type of cut desired by the surgeon,such as a line, a plug, a circle, etc., however as shown the open region260 is a crescent shape.

In use, as shown in FIG. 4A, the pressurized stream of fluid 214 flowsout of the nozzle 228 of the high pressure jet 212 and contacts thetemplate 257. Upon contact, the abrasive material in the open region 260is eroded by the pressurized stream of fluid 214, resulting in abrasiveparticles becoming entrained within the pressurized stream of fluid 214while the solid region 262 remains unchanged. As a result, the hardmaterial 200 is cut in a pattern which complements the pattern of theopen region 260. One skilled in the art will appreciate that because thesolid region 262 does not erode upon contact with the pressurized streamof fluid 214, it can be reused.

One skilled in the art will further appreciate further features andadvantages of the invention based on the above-described embodiments.Accordingly, the invention is not to be limited by what has beenparticularly shown and described, except as indicated by the appendedclaims. All publications and references cited herein are expresslyincorporated herein by reference in their entirety.

1. A method of effecting cutting during a surgical procedure,comprising: providing a surgical tool effective to deliver a pressurizedstream of a fluid through a nozzle; and delivering the pressurizedstream of fluid through the surgical tool and out of the nozzle to hardmaterial within a patient to effect cutting of the hard material withinthe patient in a desired pattern such that the fluid that cuts the hardmaterial includes a delivery liquid having a plurality of abrasive solidparticles formed from an organic material.
 2. The method of claim 1,wherein the delivery liquid is a saline solution.
 3. The method of claim1, wherein the abrasive solid particles are bioabsorbable.
 4. The methodof claim 1, wherein the abrasive solid particles are selected from thegroup consisting of polyglycolic acid, polylactic acid, polyethyleneoxide, and blends and copolymers thereof.
 5. The method of claim 4,wherein the abrasive solid particles are formed from particles having aparticle size in the range of about 5 to 200 microns.
 6. The method ofclaim 1, wherein the pressurized stream of fluid is delivered throughthe nozzle at a pressure in the range of about 1,000 to 20,000 psi. 7.The method of claim 1, wherein the abrasive solid particles are mixedwith the pressurized stream of fluid prior to delivery through thenozzle.
 8. The method of claim 1, wherein the plurality of abrasivesolid particles are entrained in the pressurized fluid stream after thepressurized fluid stream exits the nozzle.
 9. The method of claim 1,wherein the pressurized fluid stream that exits the nozzle contacts asolid material, at least a portion of which is eroded by the fluidstream to entrain the plurality of solid particles in the fluid stream.10. The method of claim 9, wherein the solid material is a rod formed ofan abrasive material.
 11. The method of claim 9, wherein the solidmaterial is a plate having a solid region and an open region, the openregion being formed in a desired shape and being occluded by an abrasiveagglomerate, such that when the plate is contacted by the pressurizedfluid stream, the hard material is cut in a pattern that is in the shapeof the open region.
 12. The method of claim 1, further comprising:providing a cutting template having a region formed of a solid materialresistant to erosion by the pressurized fluid stream and an opening insaid region forming a cutting region having a size and shapecorresponding to a desired pattern, the cutting region being occupied bya plug of abrasive material; and directing the pressurized fluid streamover the cutting template to entrain with the pressurized fluid streamabrasive solid particles eroded from the plug of abrasive material toeffect cutting of the hard material.
 13. The method of claim 12, whereinthe hard material is selected from the group consisting of bone, bonecement, and bioadhesives.
 14. A system for cutting tissue during asurgical procedure, comprising: a surgical apparatus effective todeliver a stream of pressurized fluid; and a plate having a cuttingtemplate having a region formed of a solid material resistant to erosionby the pressurized fluid and an opening in said region, the openingbeing occluded by a plug of abrasive material.
 15. The system of claim14, wherein the opening is formed in the shape of a desired cuttingpattern.
 16. The system of claim 14, wherein the abrasive solidparticles are selected from the group consisting of polyglycolic acid,polylactic acid, polyethylene oxide, and blends and copolymers thereof.17. The system of claim 14, wherein the abrasive material formed fromparticles having a particle size in the range of about 5 to 200 microns.